High-power RF systems are expensive to build and costly to operate because of their inefficiency and unreliability, primarily due to the distribution of high power levels over large distances.
Typically, high-power systems for accelerator applications use multi-megawatt microwave tubes such as klystrons. The RF power gun klystrons is usually distributed to multiple strings of cavities through high-power waveguide systems, which are expensive to produce and to operate, because of reduced efficiency and lower reliability of the distribution system. In such systems, the final power output stage is an amplifier; this gives inherently good phase and frequency control from a low-level RF reference signal, at the cost of significantly reduced efficiency.
There have been several previous attempts to control the phase and frequency of magnetrons. Unfortunately, none of those techniques have proven to be sufficiently stable, flexible, and accurate enough for use in particle accelerators.
It would also be advantageous to use the inherently high efficiency of a magnetron to provide the RF power.
It would further be advantageous to improve the phase and frequency stability of the RF output of a magnetron to make it suitable for particle accelerators and other applications.